This application claims priority under 35 U.S.C. Section 119 on Japanese Application No. 10-283553, filed Sep. 21, 1998, the disclosure of which is hereby incorporated herein by reference.
1. Field of the Invention
The present invention relates to an orientation-detecting apparatus, an orientation-detecting method, an orientation-detecting sensor device, and an orientation-designating device, all of which are used for detecting three-dimensional orientations by using an electromagnetic coupling unit.
2. Description of the Related Art
Hitherto, trackballs have been used as devices for detecting the orientation of an object in three-dimensional space. By using an encoder for detecting the rotation of a trackball about the X-axis and the Y-axis, the amount by which the trackball is rotated about the X- and Y-axes directions is detected.
In the above-described conventional trackballs, however, the rotation made about the X-, Y-, and Z-axes cannot be detected. Additionally, the rotation can be detected only as a relative value, and not as an absolute value, since the trackball detects rotational displacements about the axes.
Accordingly, it is an object of the present invention to detect orientations in three-dimensional space as absolute values.
In order to achieve the above object, according to one aspect of the present invention, there is provided an orientation-detecting apparatus including an orientation-designating device having a plurality of orientation-designating coils whose coil planes face in different directions. An orientation-detecting sensor includes a plurality of orientation-detecting coils which are radially disposed from a center position and are electromagnetically coupled to the orientation-designating coils. A selector selectively switches the orientation-detecting coils. Signals having a plurality of frequencies are transmitted and received between the selected orientation-detecting coil and the corresponding orientation-designating coil by electromagnetic coupling therebetween. A signal receiver receives a signal received by the orientation-detecting coil or the orientation-designating coil. A calculator calculates an orientation of the orientation-designating device from the signal received by the signal receiver. With this arrangement, the orientation of the orientation-designating device disposed at the center position is detected.
According to another aspect of the present invention, there is provided an orientation-detecting method. In this method, an orientation-designating device is disposed at a center position of orientation-detecting sensor, the orientation-designating device including a plurality of orientation-designating coils whose coil planes face in different directions, the orientation-detecting sensor including a plurality of orientation-detecting coils which are radially disposed from the center position and are electromagnetically coupled to the orientation-designating coils. Signals are transmitted and received between the orientation-detecting coil selected by a selector and the corresponding orientation-designating coil by electromagnetic coupling therebetween. The signal detected or received by the selected orientation-detecting coil or the orientation-designating coil is then received by a signal receiver. An orientation of the orientation-designating device in three-dimensional space is detected by calculating the orientation of the orientation-designating device by a calculator based on the signal received by the signal-receiver. The orientation of the orientation-designating device in three-dimensional space is detected according to values obtained by detecting azimuth angles xcfx86 and tilt angles xcex8 or direction vectors of the plurality of orientation-designating coils.
According to still another aspect of the present invention, there is provided an orientation-detecting sensor device which is magnetically coupled to a plurality of orientation-designating coils, whose coil planes face in different directions, provided for an orientation-designating device. The orientation-detecting sensor device includes a plurality of orientation-detecting coils radially disposed from a center position.
According to a further aspect of the present invention, there is provided an orientation-designating device including a plurality of orientation-designating coils which are electromagnetically coupled to an orientation-detecting sensor formed of a plurality of orientation-detecting coils. The plurality of orientation-designating coils are disposed in such a manner that coil planes of the orientation-designating coils face in different directions.